CN115157667A

CN115157667A - Printing nozzle suitable for biological material

Info

Publication number: CN115157667A
Application number: CN202210547745.4A
Authority: CN
Inventors: 郭如瀚; 汤文成
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2022-10-11
Anticipated expiration: 2042-05-18
Also published as: CN115157667B

Abstract

The invention discloses a printing nozzle suitable for biological materials, which comprises a driving mechanism, a piston driving part and a tubular stock bin part, wherein the driving mechanism comprises a motor, a module frame and a connecting piece, and the motor is arranged on the module frame and can drive the connecting piece to reciprocate. The tubular bin component comprises a tubular bin, a piston and a nozzle, and the piston is in interference fit with the side wall of an inner cavity of the tubular bin; the piston driving component comprises a piston rod, and the piston rod is connected with the connecting piece; the free end of the piston rod can be inserted into the inner cavity of the tubular storage bin from the first end of the tubular storage bin and is fixed with the piston through the clamping structure. The sprayer disclosed by the invention can effectively reduce the risk of bacteria infection, is simple and convenient to operate, and can be applied to various fields such as personalized organoid construction, hepatocyte treatment, tumor cell research and the like.

Description

Printing nozzle suitable for biological material

Technical Field

The invention belongs to the technical field of biological 3D printing, and particularly relates to a printing nozzle suitable for printing a trace high-viscosity biological material.

Background

The biological 3D printing technology is based on additive manufacturing concept, and uses living cells, extracellular matrix, biological factors and biological materials as raw materials to manufacture living or non-living biological products such as medical devices, tissue engineering scaffolds and tissue organs. Biological 3D printing can be classified by basic modeling unit as: zero-dimensional based micro-drop bio-3D printing, one-dimensional based micro-filament bio-3D printing, and two-dimensional based planar bio-3D printing.

The micro-drop biological 3D printing method is characterized by high forming precision, high printing speed and small and exquisite and precise forming structure, and mainly comprises micro-valve type and piezoelectric printing technologies.

As shown in fig. 1a, the printing principle of microvalve printing is to place a high speed solenoid valve 1001 between a cartridge/syringe pump 1002 and a nozzle port 1003, allowing one droplet to be printed in one open and closed cycle. The technology can realize the control of the volume of the droplets and the printing speed by adjusting the opening time and the air pressure of the high-speed electromagnetic valve 1001, the minimum volume of the printed droplets can reach nanoliter level, the printing precision is high, and the printing operation is relatively simple because of adopting a non-contact printing mode.

The micro valve type printing has the defects that the applicable biological ink has low viscosity, the highest viscosity is only about 20mPa & s, and the valve body is blocked by using the high-viscosity ink; when printing materials need to be changed, the micro valve needs to be thoroughly cleaned, but the micro valve is difficult to thoroughly clean due to the complex internal structure, and the manufacturing cost of the micro valve suitable for biological 3D printing is very high, so that the micro valve cannot be easily replaced; and, because of the difficulty in cleaning the microvalve, there is a greater risk of contamination when using bio-inks with cells.

As shown in fig. 1b, the printing principle of piezoelectric printing is that the piezoelectric tube 2001 is subjected to an excitation voltage to contract and expand, so as to drive the nozzle glass tube 2002 to vibrate together and make the internal ink generate pressure sound waves. The pressure wave propagates inside the nozzle glass tube 2002 and when it reaches the nozzle opening 2003, it drives the ejection of ink from the nozzle opening 2003, resulting in a printing operation. Compared with a micro-valve type printing method, the piezoelectric type printing method is lower in cost and high in printing precision, piezoelectric ceramics are not in direct contact with ink, and the cleaning difficulty is reduced.

Piezoelectric printing has the defects that similar to micro-valve printing, the viscosity of applicable bio-ink is low and is only about 20mPa & s at most, and the micro-droplets are formed by piezoelectric excitation oscillation, so when high-viscosity ink is used, the energy generated by excitation is not enough to exceed the jetting critical value, and the ink cannot be printed; the cells are damaged in the printing process due to the instant impact force caused by piezoelectric excitation, so that the overall cell survival rate is lower than that of the microwire type printing technology; and, the piezoelectric type printing nozzle often adopts the capillary glass pipe, and this kind of glass pipe processing technology requirement is higher, and the cost is higher, and the inside thinner of glass pipe also is more difficult on wasing.

Microwire bio 3D printing is similar to the classical melt extrusion (FDM) process, extruding material into filaments and further layer-by-layer stacking with appropriate driving force. The advantage of little silk formula printing lies in adopting solid volume replacement principle to be fit for the biological ink of higher viscosity, and the feed bin often adopts disposable syringe, greatly reduced contamination risk. The most common extrusion driving forces are pneumatic and piston. The pneumatic mode is through controlling atmospheric pressure, and the form of carrying out the volume replacement through gas propulsion piston prints. The pneumatic type has the advantages that the extrusion force range is wide, the control at the start-stop node is accurate, and the material drooling can be effectively avoided. The piston pushing type is that the biological ink is pushed through the motion of the motor directly driving the piston, the piston is pushed through the push rod to carry out volume replacement, and the piston pushing type is simple in structure, easy to operate and suitable for printing the biological ink with high viscosity.

The micro-wire biological 3D printing has the defects that the printing precision is low, the minimum is only 100 micrometers, a precise small structure is difficult to construct, and in contrast, the micro-drop printing technology can realize the precision of about 1-10 micrometers; the microwire biological 3D printing usually adopts the printing mode with the printing platform contact, and it is difficult to the printing of 96 or 384 orifice plates that the aperture is little, high hole depth, and the platform calibration operation degree of difficulty is great.

Disclosure of Invention

In order to solve the technical problems that the spray head is difficult to clean, low in printing precision and high in operation difficulty, the invention provides the printing spray head suitable for trace 3D printing of the high-viscosity biological material. The driving mechanism comprises a motor, a module frame and a connecting piece, wherein the motor is arranged on the module frame and can drive the connecting piece to reciprocate; the tubular bin component comprises a tubular bin, a piston and a nozzle, the tubular bin is provided with a hollow through hole, a first end of the tubular bin is detachably arranged on the module frame, a second end of the tubular bin is connected with the nozzle, the piston is arranged in an inner cavity of the tubular bin in a sliding mode, and the piston is in interference fit with the side wall of the inner cavity of the tubular bin; the piston driving component comprises a piston rod, the piston rod is connected with the connecting piece, and a clamping structure is arranged between the free end of the piston rod and the piston; the motor can drive the connecting piece to drive the piston rod to move towards the nozzle along a rod shaft direction, so that the free end of the piston rod can be inserted into the inner cavity of the tubular bin from the first end of the tubular bin and is fixed with the piston through the clamping structure.

In one embodiment, after the free end of the piston rod is fixed to the piston, the motor drives the piston rod in a reverse direction to slide the piston in the inner cavity of the tubular cartridge towards the first end, so that a predetermined volume of bio-ink is sucked into the tubular cartridge.

In one embodiment, the driving mechanism further comprises a screw rod, a slide rail and a screw rod slide block,

the slide rail is arranged on the module frame, the motor is connected with the first end of the screw rod in a driving way, the second end of the screw rod is rotationally connected with the screw rod slide block,

the connecting piece is fixed on the screw rod sliding block,

the slide rail with lead screw parallel arrangement, the lateral part of slider have with the recess or the sand grip that the slide rail corresponds for the motor can drive the lead screw drives the slider along slide rail reciprocating sliding.

In one embodiment, the second end of the lead screw is rotatably connected with the lead screw slide block through a bearing.

In one embodiment, the first end of the tubular magazine has an outwardly extending flange securable to the module rack through an aperture of the module rack; and/or the presence of a gas in the atmosphere,

the first end of the tubular cartridge has an inwardly extending flange for blocking the piston from exiting the tubular cartridge.

In one embodiment, the piston rod is movably connected with the connecting piece, the connecting piece is provided with a piston rod through hole, the rear end of the piston rod is provided with a flange, the free end of the piston rod can penetrate through the piston rod through hole, and the flange at the rear end of the piston rod can be blocked and limited by the edge of the piston rod through hole;

the piston driving part also comprises an electromagnet which is fixed on the connecting piece; the electromagnet is a through type direct current push rod electromagnet and comprises a brake push rod, the first end of the brake push rod penetrates out of the through hole of the electromagnet, and the first end of the brake push rod is connected with the rear end of the piston rod in an axially drivable mode.

In one embodiment, the piston driving component further comprises a supporting spring, the second end of the brake push rod penetrates out of the through hole of the electromagnet, the second end of the brake push rod is sleeved with the supporting spring, two ends of the supporting spring are supported between the electromagnet and the second end of the brake push rod,

when the printing machine is used for printing, the motor drives the connecting piece to slowly move towards the direction of the nozzle for a preset distance, the downward pressure of the supporting spring on the piston is smaller than the static friction force between the piston and the side wall of the inner cavity of the tubular stock bin, the piston keeps in place and does not move, and a gap is formed between a flange at the rear end of the piston rod and the connecting piece; and when the motor stops, the electromagnet is electrified, so that the brake push rod moves in an accelerated manner, the piston is driven to push the preset distance in the inner cavity of the tubular stock bin towards the direction of the nozzle, and the biological ink is sprayed through the nozzle to be printed.

In one embodiment, the piston driving part further comprises a flange linear bearing disposed in the piston rod through hole, and the piston rod passes through the flange linear bearing.

In one embodiment, the free end of the piston rod ends in a ball head, and a recess is provided on the end face of the piston, into which recess the ball head can be inserted.

In one embodiment, the motor is preferably a stepper motor.

The invention has the beneficial effects that:

the main innovation points and the realization mode of the patent are as follows:

1. the invention uses the structural design of a printing spray head which is excited by an electromagnet and matched with a solid volume displacement type (a piston push rod), and the solid volume displacement type printing can be similar to a micro-extrusion type printing technology and is used for extruding high-viscosity materials; the electromagnet can form a pulse excitation, is conducted to the push rod to apply micro and short positive displacement to the push rod, and is used for jet printing of the liquid drop-shaped biological material with extremely small unit volume. The two technologies can be matched with each other through mechanisms, trace printing can be carried out on the high-viscosity biological ink, and the problem that high-viscosity materials cannot be sprayed when the micro-valve or piezoelectric printing technology is adopted for trace printing is solved; the problem that a high-precision micro-printing structure is difficult to construct when a micro-extrusion printing technology is adopted to print high-viscosity materials is solved.

2. According to the invention, through the design of the solid volume displacement type spray head excited by the electromagnet, materials are sprayed and separated in the form of liquid drops, so that the printing nozzle can print on the premise of not contacting the printing platform. The printing nozzle is in a non-contact state with the printing platform in the printing process, and the problems of cross contamination, drooling and complex operation caused by platform calibration which are easy to occur when the micro-extrusion printing technology is used for printing are solved.

3. The storage bin of the invention adopts a disposable replaceable storage bin, and has no problem of cleaning for an operator. For materials containing cells and sensitive to cleanliness, the possibility of cross contamination is greatly reduced, the risk of contamination is effectively reduced, and the method is simple and convenient to operate and can be applied to various fields of personalized organoid construction, hepatocyte treatment, tumor cell research and the like. The operation of replacing materials is also very convenient and friendly.

Drawings

FIGS. 1a and 1b are prior art nozzles suitable for micro 3D printing of high viscosity biomaterials;

FIG. 2 is a perspective view of a nozzle suitable for micro 3D printing of high viscosity biomaterial according to an embodiment of the present invention;

FIG. 3 is an assembly structure diagram of the nozzle for micro 3D printing of high viscosity biomaterial according to the embodiment of the present invention;

fig. 4 is a front view of a spray head suitable for micro 3D printing of high viscosity biomaterial according to an embodiment of the present invention;

FIG. 5 isbase:Sub>A cross-sectional view taken along line A-A of FIG. 4;

FIG. 6 is a perspective view of a driving mechanism of a nozzle suitable for micro 3D printing of high viscosity biomaterial according to an embodiment of the present invention;

fig. 7a and 7b are schematic diagrams illustrating the operation of the piston driving part of the nozzle suitable for micro 3D printing of high-viscosity biomaterial according to the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings. Those skilled in the art will appreciate that the present invention is not limited to the drawings and the following examples.

As used herein, the term "include" and its various variants are to be understood as open-ended terms, which mean "including, but not limited to. The term "based on" and the like may be understood as "based at least on". The terms "first", "second", "third", etc. are used merely to distinguish different features and have no essential meaning. The terms "left", "right", "middle", and the like are used only to indicate a positional relationship between relative objects.

The embodiment of the invention provides a nozzle suitable for micro 3D printing of a high-viscosity biomaterial, as shown in fig. 2 to 7, the nozzle comprises a driving mechanism 100, a piston driving part 200 and a tubular silo part 300, the driving mechanism 100 comprises a motor 101, a module frame 106 and a connecting part 107, and the motor 101 is arranged on the module frame 106 and can drive the connecting part 107 to reciprocate. The tubular stock bin component 300 comprises a tubular stock bin 301, a piston 302 and a nozzle 304, wherein the tubular stock bin 301 is provided with a hollow through hole, the first end of the tubular stock bin 301 is detachably arranged on the module frame 106, the second end of the tubular stock bin 301 is connected with the nozzle 304, the piston 302 is arranged in an inner cavity of the tubular stock bin 301 in a sliding mode, and the piston 302 is in interference fit with the inner cavity side wall of the tubular stock bin 301. The piston driving component 200 comprises a piston rod 203, the piston rod 203 is connected with the connecting piece 107, and a clamping structure is arranged between the free end of the piston rod 203 and the piston 302. The motor 101 can drive the connection member 107 to move the piston rod 203 toward the nozzle 304 along the rod axis direction, so that the free end of the piston rod 203 can be inserted into the inner cavity of the tubular bin 301 from the first end of the tubular bin 301 and fixed with the piston 302 through the clamping structure.

The spray head suitable for trace 3D printing of the high-viscosity biological material has the replaceable tubular stock bin, the technical problem that the spray head repeatedly used for multiple times in the prior art is difficult to clean is solved, and the operation is simple and convenient. In use, the first end of the tubular cartridge 301 is first secured to the module frame 106 and the free end of the piston rod 203 is aligned with the interior of the tubular cartridge 301 outside the first end of the tubular cartridge 301. The motor 101 is started, the piston rod 203 is driven to move along the rod axis direction and is gradually inserted into the inner cavity of the tubular bin 301, in the inner cavity of the tubular bin 301, the free end of the piston rod 203 is abutted against one end of the piston 302, the piston 302 is pushed to slide towards the nozzle 304, and because the opening size near the nozzle 304 is far smaller than that of the piston 302, when the piston 302 can not slide towards the nozzle 304 in the tubular bin 301, the free end of the piston rod 203 is fixed with the piston 302 through the clamping structure. The nozzle 304 is immersed in the bio-ink, the motor 101 is started to drive the piston rod 203 reversely to slide the piston 302 in the inner cavity of the tubular bin 301 towards the first end, so that a predetermined volume of bio-ink is sucked into the tubular bin 301, and the motor 101 is stopped. And removing the bio-ink, and driving the piston rod 203 to drive the piston 302 by the starting motor 101 so as to jet and print the bio-ink through the nozzle. This repeats blotting and printing. When the biological ink needs to be replaced or the tubular bin 301 is dirty after printing of one batch is completed, the driving motor 101 withdraws the piston rod 203 from the first end of the tubular bin 301, so that a new tubular bin 301 carrying the biological ink can be directly replaced, and the next batch of experiments can be carried out without pollution.

Specifically, as shown in fig. 3 and fig. 6, the driving mechanism 100 includes a motor 101, a lead screw 102, a housing 103, a slide rail 104, a lead screw slider 105, a module frame 106, and a connecting member 107, wherein the motor 101, the slide rail 104, and the housing 103 are disposed on the module frame 106. The motor 101 is preferably a stepping motor, the motor 101 is drivingly connected to a first end of the lead screw 102, and a second end of the lead screw 102 is rotatably connected to the lead screw slider 105, for example, by a bearing. The connecting piece 107 is fixed to the lead screw slider 105. The slide rail 104 is parallel to the screw rod 102, and a groove or a convex strip corresponding to the slide rail 104 is arranged on the side of the slide block 105, so that the motor 101 can drive the screw rod 102 to drive the slide block 105 to slide along the slide rail 104 in a reciprocating manner.

As shown in fig. 2-5, the tubular cartridge member 300 comprises a tubular cartridge 301, a piston 302, a temperature control module 303, and a nozzle 304, the tubular cartridge 301 having a hollow through-hole, preferably having a circular cross-section. The first end of the tubular cartridge 301 is removably attached to the module frame 106. In this embodiment, the first end of the tubular cartridge 301 has an outwardly extending flange that can be passed through a hole in the module frame 106 and secured to the module frame 106. The second end of the tubular stock bin 301 is connected with the nozzle 304, the nozzle 304 is preferably connected with the tubular stock bin 301 through luer threads, the piston 302 is slidably arranged in the inner cavity of the tubular stock bin 301, and the piston 302 is in interference fit with the side wall of the inner cavity of the tubular stock bin 301. The temperature control module 303 covers the outside of the tubular bin 301 and is used for monitoring the temperature in the printing process.

Preferably, the first end of the tubular cartridge 301 has an inwardly extending flange for blocking the piston 302 from escaping from the tubular cartridge 301. Of course, the inwardly extending flange may not be provided and the piston 302 may be manually placed in the interior cavity of the tubular cartridge 301 or removed from the piston rod 203.

As shown in fig. 2 to 5, in the present embodiment, the piston driving member 200 includes an electromagnet 201, a piston rod 203, a flange linear bearing 204, and a support spring 205.

In this embodiment, the piston rod 203 is movably connected to the connecting member 107. The connecting piece 107 is provided with a piston rod through hole, the rear end of the piston rod 203 is provided with a flange, the free end of the piston rod 203 can penetrate through the piston rod through hole, and the flange at the rear end of the piston rod 203 can be blocked and limited by the edge of the piston rod through hole.

The electromagnet 201 is fixed on the connecting piece 107, the electromagnet 201 is a through type direct current push rod electromagnet and comprises a brake push rod 202, the first end of the brake push rod 202 penetrates out of a through hole of the electromagnet 201, and the first end of the brake push rod 202 is preferably in axial drivable connection with the rear end of the piston rod 203 through threads; the second end of the brake push rod 202 penetrates through the through hole of the electromagnet 201, the second end of the brake push rod 202 is sleeved with a support spring 205, and two ends of the support spring 205 are supported between the electromagnet 201 and the second end of the brake push rod 202.

Preferably, the flange linear bearing 204 is disposed in the piston rod through hole, and the piston rod 203 passes through the middle of the flange linear bearing 204, so that eccentricity is not generated when the piston rod 203 slides in the axial direction.

A clamping structure is arranged between the free end (front end) of the piston rod 203 and the piston 302, for example, the end of the free end of the piston rod 203 is a ball head, and a recess is arranged on the end surface of the piston 302, and the ball head can be embedded into the recess. Therefore, during the process that the motor 101 drives the connecting piece 107 to drive the piston rod 203 to move towards the nozzle 304 along the rod axis direction, the free end of the piston rod 203 can be inserted into the inner cavity of the tubular stock bin 301 from the first end of the tubular stock bin 301 to slide, and is fixed with the piston 302 through the clamping structure.

The working principle of the nozzle suitable for micro 3D printing of high viscosity biomaterial according to the above embodiment is described below.

A printing preparation stage:

before printing begins, the tubular bin 301 is not installed on the spray head, and the electromagnet 201 is in a power-off state. The starting motor 101 drives the piston rod 203 to move towards the motor direction until the movement is stopped after a displacement switch arranged on the module frame 106 is triggered, and the system is in an initial state.

The first end of the tubular cartridge 301 is secured to the module frame 106 and the free end of the piston rod 203 is aligned with the interior cavity of the tubular cartridge 301 outside the first end of the tubular cartridge 301. The motor 101 is started, the piston rod 203 is driven to move along the rod axis direction and is gradually inserted into the inner cavity of the tubular bin 301, the free end of the piston rod 203 is abutted to one end face of the piston 302 in the inner cavity of the tubular bin 301, the piston 302 is pushed to slide towards the nozzle 304, and the size of the opening near the nozzle 304 is far smaller than that of the piston 302, so that when the piston 302 cannot slide towards the nozzle 304 any more in the tubular bin 301, the free end of the piston rod 203 is fixed with the piston 302 through the clamping structure. The nozzle 304 is immersed in the bio-ink, the piston rod 203 is driven by the motor 101 in reverse to drive the piston rod 302 to slide in the inner cavity of the tubular cartridge 301 towards the first end, so that a predetermined volume of bio-ink is sucked into the tubular cartridge 301, and the motor 101 is stopped, as shown in fig. 7 a.

A printing stage:

when printing is started, the motor 101 is started, the screw rod 102 is controlled to rotate at a low speed, and the connecting piece 107 is driven to slowly move towards the direction of the nozzle 304 for a preset distance, the lowered preset distance determines the printing volume, and the printing volume is small, and the preset distance is generally only 0.1-1mm. In this case, since the movable connection structure is provided between the piston rod 203 and the connecting member 107, and the piston 302 and the inner cavity sidewall of the tubular bin 301 are in interference fit, the static friction force generated by the piston 302 and the inner cavity sidewall of the tubular bin 301 cannot be overcome, that is, the downward pressure of the supporting spring 205 on the piston 302 is smaller than the static friction force between the piston 302 and the inner cavity sidewall of the tubular bin 301, so that the piston rod 203 cannot be moved by the descending of the connecting member 107, that is, the piston 302 remains in place, as shown in fig. 7 b. Thus, since the connection member 107 is lowered by a predetermined distance and the piston rod 203 is relatively stationary, a gap is formed between the rear end flange of the piston rod 203 and the connection member 107, and the printing accuracy and the volume of bio-ink are determined by the distance of the gap. When the preset gap is generated, the motor 101 is stopped, the electromagnet 201 is electrified, so that the brake push rod 202 moves downwards at an accelerated speed, the piston rod 203 and the piston 302 are driven to push the preset distance towards the nozzle 304 in the inner cavity of the tubular bin 301, and the movement is stopped until the rear end flange of the piston rod 203 abuts against the connecting piece 107. Thus, by the above-described printing mechanism, the momentum of the bio-ink is transmitted and ejected from the nozzle 304, and printing is performed by one printing unit. Printing by the plurality of printing units is repeated in this manner.

A post-printing stage:

when the biological ink needs to be replaced or the tubular silo 301 is dirty after printing of one batch is completed, the driving motor 101 withdraws the piston rod 203 from the first end of the tubular silo 301, so that a new tubular silo 301 carrying the biological ink can be directly replaced, and the next batch of experiments can be performed without pollution.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Printing head suitable for biological materials, characterized in that it comprises a driving mechanism (100), a piston driving member (200) and a tubular magazine member (300),

the driving mechanism (100) comprises a motor (101), a module frame (106) and a connecting piece (107); the motor (101) is arranged on the module frame (106) and is used for driving the connecting piece (107) to reciprocate;

the tubular bin component (300) comprises a tubular bin (301), a piston (302) and a nozzle (304), the tubular bin (301) is provided with a hollow through hole, a first end of the tubular bin (301) is detachably arranged on the module frame (106), a second end of the tubular bin (301) is connected with the nozzle (304), the piston (302) is arranged in an inner cavity of the tubular bin (301) in a sliding mode, and the piston (302) is in interference fit with the side wall of the inner cavity of the tubular bin (301);

the piston driving component (200) comprises a piston rod (203) and a pulse driver, the piston rod (203) is connected with the connecting piece (107), and the free end of the piston rod (203) is connected with the piston (302); the pulse driver is used for generating a pulse signal for controlling the micro-stroke of the piston rod (203);

the motor (101) is used for driving the connecting piece (107) to drive the piston rod (203) to move towards the nozzle (304) along the rod shaft direction, so that the free end of the piston rod (203) can be inserted into the inner cavity of the tubular bin (301) from the first end of the tubular bin (301).

2. Print head according to claim 1, characterized in that the pulse driver is an electromagnet (201), the electromagnet (201) being fixed to the connecting piece (107); the electromagnet (201) is a through type direct current push rod electromagnet and comprises a brake push rod (202), the first end of the brake push rod (202) penetrates out of a through hole of the electromagnet (201), and the first end of the brake push rod (202) is connected with the rear end of the piston rod (203) in an axially drivable mode.

3. Print head according to claim 2, characterized in that, after the free end of the piston rod (203) is fixed to the piston (302), the motor (101) drives the piston rod (203) in reverse to slide the piston (302) in the inner cavity of the tubular magazine (301) towards the first end, so as to suck a predetermined volume of bio-ink in the tubular magazine (301).

4. Print head according to claim 1, characterized in that the drive mechanism (100) further comprises a screw (102), a slide (104) and a screw slide (105),

the slide rail (104) is arranged on the module frame (106), the motor (101) is connected with the first end of the screw rod (102) in a driving way, the second end of the screw rod (102) is rotationally connected with the screw rod slide block (105),

the connecting piece (107) is fixed on the screw rod sliding block (105),

the slide rail (104) and the screw rod (102) are arranged in parallel, and the side part of the screw rod slide block (105) is provided with a groove or a raised line corresponding to the slide rail (104), so that the motor (101) can drive the screw rod (102) to drive the screw rod slide block (105) to slide along the slide rail (104) in a reciprocating manner.

5. Print head according to claim 4, characterized in that the second end of the screw (102) is rotatably connected to the screw slide (105) by means of a bearing.

6. Print head according to claim 1, characterized in that the first end of the tubular magazine (301) has an outwardly extending flange, which can be fixed to the module frame (106) through a hole of the module frame (106); and/or the presence of a gas in the gas,

the first end of the tubular cartridge (301) has an inwardly extending flange for blocking the piston (302) from escaping the tubular cartridge (301).

7. Print head according to claim 1, characterized in that the piston rod (203) is movably connected to the connecting part (107), the connecting part (107) has a piston rod through hole, the rear end of the piston rod (203) is provided with a flange, the free end of the piston rod (203) can pass through the piston rod through hole, and the rear end flange of the piston rod (203) can be stopped and limited by the edge of the piston rod through hole.

8. Print head according to claim 7, characterized in that the second end of the brake push rod (202) is sheathed with a support spring (205), the two ends of the support spring (205) being supported between the electromagnet (201) and the second end of the brake push rod (202);

during printing, the motor (101) drives the connecting piece (107) to slowly move towards the nozzle (304) for a preset distance, the downward pressure of the supporting spring (205) on the piston (302) is smaller than the static friction force between the piston (302) and the side wall of the inner cavity of the tubular stock bin (301), the piston (302) is kept in place, and a gap is formed between the rear end flange of the piston rod (203) and the connecting piece (107); and the motor (101) stops, the electromagnet (201) is electrified, so that the brake push rod (202) moves in an accelerated manner, the piston (302) is driven to push the preset distance in the inner cavity of the tubular stock bin (301) towards the direction of the nozzle (304), and the bio-ink is ejected through the nozzle (304) for printing.

9. Print head according to claim 6, wherein the piston drive member (200) further comprises a flange linear bearing (204), the flange linear bearing (204) being arranged in the piston rod through hole, the piston rod (203) passing through the flange linear bearing (204).

10. Print head according to claim 1, characterized in that the free end of the piston rod (203) ends with a ball head, with a recess on the end face of the piston (302), into which recess the ball head can be inserted.